Environmental enrichment for Rett

Australian researchers have found that environmental enrichment improves motor coordination in a mouse model of Rett syndrome.

The researchers studied heterozygous female and hemizygous male mice to evaluate whether environmental factors influence the outcome of Rett syndrome.

Rett syndrome is a severe mental disability affecting girls, caused by a mutation in the MeCP2 gene, located on the X chromosome. Boys with the mutation usually die in utero or shortly after birth, as they have no normal copy of the gene.

The mouse model was developed by Dr Greg Pelka and Professor Patrick Tam from the Children's Medical Research Institute in Sydney, along with Professor John Christodoulou from the Children's Hospital at Westmead.

Lead author Mari Kondo, a PhD student in Associate Professor Tony Hannan's lab at the Howard Florey Institute in Melbourne, said environmental enrichment significantly improved the ability of Rett syndrome mice to learn and maintain tasks that required coordinated movements.

The team also discovered that levels of brain-derived neurotrophic factor (BDNF), a protein essential to neuronal growth, was higher in enriched mice than in standard-housed mice.

The environmental enrichment entailed housing the mice in a larger cage than normal, Kondo said.

"In the larger cage we include things like running wheels, paper tunnels, wooden toys, plastic toys, in lots of different colours," she said. "Anything that gets them interested and makes them move so that they get sensory, motor and cognitive stimulation.

"Enrichment has already been shown to be very effective in other mouse models and other neurological diseases such as Huntingdon's, Alzheimer's and Fragile X mental retardation, so this is another one to add to the list of diseases where enrichment has a positive effect."

Patrick Tam said the next phase of the research was to study whether enrichment worked for cognitive function, which will be carried out at the CMRI.

The work was published last week in the European Journal of Neuroscience.